Resinous compositions and process of making the same



and process of making the same.

' the two resinous compositions occurs. are thus caused to come out ofsolution in such Patented Sept. 17, 1935 UNITED 'STATES' RESINOUSCOMPOSITIONS AND PROCESS OF MAKING THE SAME Paul F. Schlingman and RoyH. Kienle, Schenectady, N. Y., assignors to General Electric Company, acorporation of New York Serial No. 539,145

No Drawing. Application May 21, 193 1,

8 Claims.

This invention relates to resinous compositions Specifically, it isconcerned with resinous compositions produced in a novel manner from aphenol, aromatic amine and aldehyde, the resulting compositions havinggood fiow, being easily moldable at relatively low'molding pressures,without the addition of fillers, to translucent homogeneous products ofhigh mechanical strength and very good dielectric properties.

In a copending application of Roy H. Kienle, Serial No. 539,146, filedconcurrently herewith and assigned to the assignee of the presentapplication, there is disclosed and claimed resinous compositions of thephenolic type which aremoldable without the addition of fillers to yieldtranslucent products of good dielectric strength. Such products whileuseful in numerous applications do not possess sufficient mechanicalstrength for certain other applications. It is, therefore, one of theprincipal objects of the present invention to mechanically strengthenthe resinous compositions of the type disclosed in the said Kienleapplication without resorting to the conventional method of addingfillers. Another object of the invention is to improve the dielectricproperties of the resinous compositions of the type referred to above.Other and further objects of this invention will be more apparent as thedescription thereof proceeds.

In accordance with our invention an aromatic amine, such as aniline, isreacted with an aldehyde, such as formaldehyde, in the presence of anacid and in aqueous solution'to a certain definite point. To thisreacted mass is added a suitable solution of a. phenolic resin taken ata definite stage in its preparation according to methods more fully setforth insaid Kienle application above referred to' and a mutualprecipitation of The resins In order to more fully illustrateourinvention the following descriptive examples are given:

' ExdmpleI A. 93 parts by weight (1.0 mol) aniline.

parts by volume (1.0 mol) con. HCI 102 parts by volume (1.1 mol) 32.5%formaldehyde are mixed together ina suitable quantity of water, say,1000 parts by volume, and the mixture allowed to stand at roomtemperature (2530 C.) for one hour with occasional stirring.

B. A resin based on the following formula is made according to the usualphenolic resin tech- The resin is boiled down to a 30 second cure on 160C. hot, plate. The cure point of the resin is not necessarily fixed asindicated but may be within the approximate limits: 30 and seconds 15 at160 C. A

The aqueous acid solution of aromatic aminealdehyde condensation productproduced in A is diluted with a relatively large volume of water, say,5000 parts by volume. 600 parts by volume 20 of a 50% alcoholic solutionof the phenolic resin produced in B is added to a large volume of water,say, 4000 parts by volume with rapid stirring, and then 400 parts byvolume of a 50% alkali solution,

e. g. NaOH is added. In place of alcohol any 25 suitable Water-misciblesolvent may be used, for example, acetone, dioxan, etc., or suitablemixtures thereof, to obtain a solution of the phenolic resin. Uponcomplete solution of the resin B in the large volume of water, the aboveprepared solution in 30 water of the aromaticamine-aldehyde'condensation product is added thereto with stirring.

A precipitate is obtained. Any excess alkali is range of moldingtemperatures is about C.

to 0., with pressures up to about 4000 lbs. sq. in. The above example ismerely illustrative of a typical resin which may be produced inaccordance with the present invention. It will be noted 45 that in thisexample the phenolic resin is in excess of the aromatic amine-aldehydecondensation product. Hence excess alkali is present in the mass afterprecipitation and is neutralized with acid. It is apparent that theproportions 5 of phenolic resin and aromatic amine-aldehyde condensationproduct may be so chosen that the alkali in one just compensates for theacid in the other, making no neutralization by acid or' alkalinecessary; or the proportions of phenolic 55 resin and aromaticamine-aldehyde condensation product may be chosen so that there is anexcess of acid present after precipitation, in which case it isneutralized with alkali.

Any of the resins prepared as outlined in the 60 above mentioned Kienleapplication may be utilized in the present; invention. To illustratefurther:

Example II A liquid .phenolic resin is made by rapidly heating a mixtureof:

Cresol 1200 parts by weight Paraformaldehyde 680 parts by weightTriethanolamine 100 parts by weight CaBrz solution -5 120 parts byvolume (33% aqueous solution) to 90 C., and immediately chilling. Theresulting resin is aged for three weeks at room temperature or until itjust starts to become opaque. The resin so prepared may be used in placeof the phenolic resin employed in Example 1.

Example III The liquid phenolic resin obtained in accordance with themethod outlined in Example II is heated at 90 C.-120 0., until a sampleshows a two minute cure or under at 160 C. hot plate. This resin can beutilized in place of the phenolic resin employed in Example I.

' Example IV A cresol resin is prepared by reacting I Parts by weight413 Cresol Aqueous formaldehyde (40%) 320 Water 70 NHlOH (28%) 24according to well known phenolic resin technique. The resin is carriedto approximately a 30 sec- 0nd cure at 160 C. and utilized in place ofthe phenolic resin employed in Example 1.

Example V An acid catalyzed resin is prepared by reacting:

Parts by weight Phenol Aqueous formaldehyde (40%) 92 Water 18 H2804.1.65

Example VI Another example of an acid catalyzed phenolicresin is thefollowing:

Parts by weight Phenol Paraformaldehyde 36 HCl (10%) 2 are reactedaccording to the procedure given in Example V. This resin is used inplace of the phenolic resin employed in Example I.

In this case the resin will mold under heat and pressure to theiniusible state without addition of any methylene-containing'body.

It is to be understood that the process is not employed and otheraldehydes may be used in place of formaldehyde in the preparation of thephenolic resin. Similarly, aniline is merely typi "cal of any aromaticamine which may be used in the preparation of the aromaticamine-aldehyde condensation product. The proportion of aldehyde employedin the preparation of the aromatic amine-aldehyde condensation productis not limited to that given in the illustrative examples. It may, forexample, vary from about 1.0 mol to about 3.0 mols when the mol ratio ofamine to acid is 1:1.

The addition of almost any dye substance which can be either dispersedor dissolved in the alkaline or alcoholic solution of the resin resultsin a colored precipitate which upon molding imparts the same color tothe molded product. Where particularly light colored substances aredesired, light colored pigment materials can be mechanicallyincorporated either as such in the dry resinous powder prior to molding,or as a dispersion in the liquid phase just previous to theprecipitation procedure. The resulting molded parts will, of course, nolonger be translucent; nevertheless their opacity will not beobjectionable since the resulting colors will be surprisingly light anduniform.

The addition of fillers to the resinous products before molding, whilenot necessary, is not precluded. Such addition will, of course, add tothe mechanical strength of the molded product.

' The following table compares a typical resin obtained by the presentinvention and containing no added filler (resin X) with'a standardwellknown molding composition containing phenol molding resin, filler,and coloring matter (resin Y) and with a typical phenolic precipitatedresin containing no added filler (resin Z) obtained by means of theinvention disclosed in the copending application of Roy H. Kienlereferred to .above.

(Resin X) (Resin Y) (Resin Z) Impact strength 1 0-1. 2 70 71 Modulus oirupture 10, 000 8, 000 8, 000 Dielectric constant 5. 5 6. 0 5. 0 Powerfactor 25 0., 1000 cycles: (a) Dry 2. 0-2. 3? 3. 5% 3. 7? (a Wet 2. 5-3.9.0% 5. Dielectric strength.-. 310 v/mi v/mil 250 v/ What we claim asnew and desire to secure by Letters Patent of the United States, is:

1. The process of making a moldable composition which comprises reactingat room temperature an aromatic amine with an aldehyde in the amine andaldehyde to form a precipitate,

neutralizing any excess alkali or acid, washing and drying theprecipitate.

2. The process of making a moldable composition which comprises reactingat room temperature aniline and formaldehyde in aqueous acid solution toform a resinous condensation product v in solutiomseparately reacting aphenol and formaldehyde to a stagewhere the resin formed has a curepoint or approximately 30 seconds at 160 0., dissolving said lastmentioned resin in alcohol, adding; alkali thereto, adding this solutionto the solution of resinous condensation product iormed from the anilineand formaldehyde thereby forming a precipitate, neutralizing excessalkalror acid, washing and drying theprecipitate.

3. The process of making a molded product which comprises reacting atroom temperature an aromatic amine and an aldehyde -in aqueous acidsolution to form a resinous condensation product in solution. separatelyreacting a phenol and aldehyde to. a stage where the resin iormed has acure point at 160 C. within the approximate lim- -.its 30-120 seconds,dissolving said last mentioned resin in 'awater-miscible solvent, addingalkali vthereto, adding this solution to the solution of resinouscondensation product formed from the amine and aldehyde thereby forminga precipitate,-neutralizing excess alkali. or acid, washing and dryingthe precipitate, and molding under heat and pressure.

4; The processor making a'molded product.

whichccmprises reacting at room temperature aniline and formaldehyde inaqueous acid solu- 1 ticn toform a resinous condensation product insolution, separately reacting a phenol and form aldehyde to a. stagewhere the resin formed has a cure point 0! approximately -seconds at 1600., dissolving said last mentioned resin in alcohol, adding alkalithereto, adding this solution to the solution 0! resinous condensationproduct formed '5 irom the aniline and formaldehyde thereby forming aprecipitate, neutralizing excess alkali or acid. washing and drying theprecipitate, and

molding at a temperature oi about -160" C.

' 30-120 seconds.

6. A moldable' resinous composition comprising the washed anddriedprecipitate obtained by treating anaqueous' acid solution of an aniline-20 formaldehyde condensation product with an alkaline solution of aphenolic resin having a cure point. at C. of approximately 30 seconds.7. An article comprising essentially the cured resinous'composition ofclaim 5. 26'

8. An article comprlsing'essentially'the cured resinous composition ofclaim'6. PAUL 1". SCHLINGMAN,

1 ROY H. KIENLE.

